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Are Eggshells Good for Citrus Trees?

Whenever I eat eggs, I find myself thinking about how I can repurpose the shells instead of just throwing them away. Citrus trees, like my Meyer lemon tree, are heavy feeders of fertilizer and can benefit from many food scraps. But does this include eggshells? I did a bit of research to find out if eggshells are good for citrus trees. Here’s what I found.

Eggshells are high in calcium and have trace amounts of magnesium, both of which are good for citrus trees. These nutrients help prevent disease, keep a balanced soil pH, and assist with overall plant growth. The best way to apply eggshells as a citrus tree fertilizer is to dry and crush them into a fine powder.

So, while eggshells are good for citrus trees, are there any other benefits? And how many eggshells should you use? Let’s find out more.

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What Are Eggshells Good For?

lemon tree with eggshells as fertilizer

Like many kitchen scraps, eggshells have quality nutrients that help benefit plant and microbial life. When broken down, these nutrients make for a great fertilizer for growing and fruiting citrus trees. So, what exactly is in eggshells and what are they good for?

Eggshells are high in calcium and have trace minerals such as selenium and magnesium. While it’s known that these nutrients help trees with disease resistance and soil pH, they also promote healthy blossoms and photosynthesis.

Without sufficient calcium, citrus tree blossoms could start to rot and fall off. But while calcium is important, there are many other nutrients you may need to supplement to promote a healthy tree.

If you think your citrus tree could use a good, balanced, homemade fertilizer, check out my post on how to craft your own homemade fertilizer blend for your citrus tree.

How Do You Apply Eggshells As Fertilizer?

How you apply eggshells impacts how well your citrus tree absorbs the nutrients. While you can simply provide your tree with crushed eggshells, you can take it a step further if you wish.

The best way to apply eggshells as a fertilizer is to first dry and powder them. Trees will have an easier time absorbing nutrients from a powder rather than in chunks. You can dry your eggshells by baking them on a sheet in the oven at 250ºF for 30 minutes. After, use a blender to turn them into a fine powder.

Once your eggshells are dried and powdered, you can either mix them into fertilizer or apply them directly to the soil. The powder will slowly release calcium and other nutrients over the next few to several months, depending on the watering and weathering of the soil.

If you don’t need to give your trees a quick calcium uptake, then simply burying crushed eggshells for a slower decomposition will work fine (this is what I do).

Keep in mind that citrus trees can have shallow roots, so if you’re applying some fertilizer under the soil, be careful not to dig too deep.

If you’re looking to add other essential nutrients to your citrus tree’s soil, I spent a few hours putting together a guide on the best citrus tree fertilizers you can buy, so feel free to check it out.

How Many Eggshells Should You Use?

It’s hard to over-apply eggshells in your citrus tree soil as it takes a lot to overpower the tree. Generally, you don’t need to worry about the amount, unless you run a large-scale egg farm. However, if you’d still like an idea of the amount, here’s a quick breakdown.

If you decide to use eggshells for your citrus trees, they should comprise about 10-20% of the overall fertilizer. Eggshells aren’t potent and can be easily dispersed through the soil, so if you happen to go over this amount, your citrus trees will be fine.

Generally, when it comes to fertilizer, citrus trees prefer an NPK (nitrogen, phosphorus, potassium) ratio of 2-1-1 or 3-1-1. The NPK of eggshells is 1-0.4-0.1. So, using 2/3 grass clippings or other high nitrogen ingredients along with 1/3 eggshells and banana peels will provide a good balance of nutrients.

Remember that eggshells can make soil slightly more alkaline, and since citrus trees prefer an acidic pH of 6.0-7.0, you won’t want to apply too much. When it doubt, you could always perform a quick test of your soil’s pH.

When Should You Fertilize Your Citrus Tree With Eggshells?

The best time to fertilize your citrus tree with eggshells is at the start of spring. At this time, your citrus trees will begin its growing period and will need a lot of nutrients. Eggshells can help provide a boost shortly before your tree starts growing and fruiting again.

As with most plant fertilizing, the best time is at the start of spring. Avoid fertilizing in winter since the nutrients can go unused and will likely wash away. Also, avoid applying high nitrogen fertilizer in the winter as nitrogen can burn the tree and its roots if left for too long in high concentrations.

Final Thoughts

Eggshells are great for citrus trees. They have a lot of calcium and other trace minerals that can help your tree grow and remain healthy. You can choose to either crush and bury the eggshells or dry and powder them. Either way, you can’t go wrong.

I personally prefer to just bury them crushed and let them break down over time, but if your citrus tree could use a faster absorption of calcium and other nutrients, powdering them would be a good idea.